Abstract: An expandable device for use in tubulars. The device comprises an outer tubular having a series of slots therein, with the slots being arranged about the exterior of the outer tubular. The device further includes an inner tubular disposed within the outer tubular, and a setting tool for moving the outer tubular in a first direction in order to expand the outer tubular along the slots. In one preferred embodiment, the slots are arranged about the outer tubular in a spiral pattern. In yet another preferred embodiment, the slots are arranged about the outer tubular in a first spiral pattern and wherein the first spiral pattern extends to a second spiral pattern. The setting tool, in one embodiment, comprises an outer setting sleeve connected to the outer tubular and a mandrel being connected to the inner member, and wherein the outer setting sleeve causes a downward force against the outer tubular so that the outer tubular expands. A method of expanding a device within a tubular is also disclosed.

Abstract: A self-retaining cementing wiper plug with a packer element has two or more steel or carbide tipped holddown fingers or slips extending radially outward from the plug for engaging the inner surface of the casing and preventing the plug from moving uphole over time and potentially interfering with other downhole apparatus such as a pump. The packer element in the wiper plug is actuated when the plug is supported by an obstruction under the plug and then compressed, the packer being maintained in compression by the holddown fingers.

Abstract: A borehole closure includes a supply line made of plastic and having formed therein a longitudinal passage between a feed end for inlet of an impregnating fluid and a discharge end. The supply line is formed with transverse passages, each covered by a sealing ring. A non-return valve is provided to block a flow of impregnating fluid in the direction toward the feed end. The supply line is sealingly surrounded by an inflating tube to define an elongate annular chamber therebetween which is in communication with the transverse passages. A rupture assembly having a rupture disk is secured at an end surface of the discharge end of the supply line and constructed to burst when a pressure applied by the impregnating fluid exceeds a predetermined value.

Abstract: An inflatable sealing assembly integrated with a flow carrier which seals the inside of the flow carrier upon detection of a physical condition (e.g. fluid pressure). The inflatable sealing assembly includes a housing, a compartment in the interior of the housing for storing an inflatable sealing device, an inflating mechanism, and a sensor. Upon detection of the physical condition in the exterior and/or interior of the flow carrier, the sensor activates the inflating mechanism, preferably automatically, to inflate and deploy the inflatable sealing device which seals off the inside of the flow carrier. The inflatable sealing device may be an air bag.

Abstract: A tubing retrievable safety valve (50) having a non annular hydraulic chamber (60) in a sidewall portion thereof is operable to received a communication tool (100) therein such that relative rotation between at least a portion of the communication tool (100) and the tubing retrievable safety valve (50) is substantially prevented. The communication tool (100) is operable to create a fluid passageway (150) between the non annular hydraulic chamber (60) and the interior of the tubing retrievable safety valve (50) by penetrating through the sidewall portion and into the non annular hydraulic chamber (60). Thereafter, when a wireline retrievable safety valve (44) is positioned within the tubing retrievable safety valve (50), hydraulic fluid is communicatable thereto through the fluid passageway (150).

Abstract: A tubing assembly including a tubing string and tubing hanger provides a fluid passage with backpressure threads for securing a backpressure plug in a fluid-tight seal below the tubing hanger, so that the tubing hanger can be removed from the tubing string. The back pressure threads are preferably incorporated in a backpressure adapter pin connected between the tubing string and the tubing hanger. The adapter pin may also incorporate external weight-bearing shoulders for snubbing and/or suspending the tubing assembly. The backpressure plug is inserted or removed using a backpressure plug tool that slides through a packing in a pressurized casement that maintains pressure in an axial passage through a control stack of the wellhead.

Abstract: Disclosed is a method of either plugging or lining a wellbore or casing using a polymer member into which stored energy or shape memory has been introduced. The shape memory is introduced into the member by reducing its diameter, such as by compressing the member using a rolling mill machine or stretching the member axially. Next, the member is lowered into a desired location in the wellbore or casing and subjected to conditions causing at least partial recovery of the anelastic strain. The conditions causing recovery of the anelastic strain can include heat from the reservoir surrounding the wellbore, heat introduced into the wellbore, solvents, and combinations thereof. Recovery of the anelastic strain causes the member to expand in diameter, thus plugging or lining the wellbore or casing at the desired location.

Abstract: A system for communicating hydraulic fluid to a wireline retrievable safety valve (44) comprises a tubing retrievable safety valve (50) having a non annular hydraulic chamber (60) in a sidewall portion thereof and a communication tool (100) that is selectively locatable within the tubing retrievable safety valve (50). The communication tool (100) creates a fluid passageway (150) between the non annular hydraulic chamber (60) and the interior of the tubing retrievable safety valve (50) by penetrating through the sidewall portion and into the non annular hydraulic chamber (60). Thereafter, when the wireline retrievable safety valve (44) is positioned within the tubing retrievable safety valve (50), hydraulic fluid is communicatable thereto through the fluid passageway (150).

Abstract: Aspects of the present invention provide apparatus and methods of releasing a plug. In one aspect, a plug and ball seat assembly for releasing a plug is disclosed. The assembly is selectively maintained in a housing using a mounting system. The plug and ball seat assembly includes a ball seat selectively connected to the plug. The mounting system is designed such that disengaging the ball seat from the plug also disengages the plug from the housing, thereby releasing the plug. In another aspect, a method of releasing a plug includes selectively connecting a ball seat to the plug and disposing the plug and ball seat assembly within a tubular. When the plug is ready for release, the ball seat is disconnected from the plug and allowed to move axially relative to the plug. In turn, the plug and ball seat assembly disconnects from the tubular and releases downhole.

Abstract: A drillpipe sub (30) comprises a shaft (32), a first frustoconical member (34) encircling, and fixedly mounted on, the shaft (32), and a second, opposed frustoconical member (36) encircling, and slidably mounted on, the shaft (32). The first frustoconical member (34) is bonded at its base (38) to the base (40) of the second frustoconical member (36).

Abstract: The present invention generally relates to apparatus and methods for completing a well. Particularly, the present invention relates to a single-direction plug for use with cementing applications and with drilling with casing applications. One embodiment comprises a cement plug for installation in a wellbore casing. The plug includes a body and gripping members for preventing movement of the body in a first axial direction relative to the casing. The plug further comprises a sealing member for sealing a fluid path between the body and the casing. The plug is movable in a second axial direction with fluid pressure but is not movable in the first direction due to fluid pressure.

Abstract: A method for the treatment of a subterranean formation penetrated by a well in which, first and second flow paths are established from the wellhead into the vicinity of the formation. A plugging fluid comprising a suspension of a particulate plugging agent in a carrier liquid is circulated into the first flow path and into contact with the wall of the well within the subterranean formation. The carrier liquid is separated from the particulate plugging agent by circulating the carrier liquid through a set of openings leading to the second flow path, which are dimensioned to allow the passage of the carrier liquid while retaining the particulate plugging agent in contact with the set of openings. The circulation of the plugging fluid continues until the particulate plugging agent accumulates to form a bridge packing within the well.

Abstract: A blanking plug device, system and method of use, wherein the plug device has an anchoring portion for securing the blanking plug device within a tubing string or other well conduit. In preferred embodiments, the anchoring portion comprises a locking device such as the Extreme SUR-SET® locking system. However, other anchoring mechanisms may be utilized as well. The blanking plug device has a lower plug portion that incorporates a screening section. The screening section permits flow of fluid through the sidewall of the plug portion while substantially preventing the passage of solid particles.

Abstract: Disclosed is a method of either plugging or lining a wellbore or casing using a polymer member into which stored energy or shape memory has been introduced. The shape memory is introduced into the member by reducing its diameter, such as by compressing the member using a rolling mill machine or stretching the member axially. Next, the member is lowered into a desired location in the wellbore or casing and subjected to conditions causing at least partial recovery of the anelastic strain. The conditions causing recovery of the anelastic strain can include heat from the reservoir surrounding the wellbore, heat introduced into the wellbore, solvents, and combinations thereof. Recovery of the anelastic strain causes the member to expand in diameter, thus plugging or lining the wellbore or casing at the desired location.

Abstract: An apparatus, system, and method useful for providing a seal with a surface includes a seal assembly having a seal body constructed at least partially of elastomeric material and at least one shape memory alloy (SMA) wire. The SMA wire is capable of encouraging at least part of the seal body into engagement with the surface.

Abstract: A non-metallic element system is provided which can effectively seal or pack-off an annulus under elevated temperatures. The element system can also resist high differential pressures without sacrificing performance or suffering mechanical degradation, and is considerably faster to drill-up than a conventional element system. In one aspect, the composite material comprises an epoxy blend reinforced with glass fibers stacked layer upon layer at about 30 to about 70 degrees. A downhole tool, such as a bridge plug, frac-plug, or packer, is also provided. The tool comprises a first and second support ring having one or more tapered wedges, a first and second expansion ring, and a sealing member disposed between the expansion rings and the support rings.

Abstract: A through tubing casing plug is disclosed. It features a stack of nested cup shaped elements that initially slope to reduce the run in diameter. The stack is compressed to force the periphery of the nested cups to move outwardly so that the collective outer surfaces of the cups can seal on the casing. The cups have sufficient initial thickness so that they remain intact despite some radial growth resulting from the compression process. In a particular example, the run in dimension is 2.13 inches and the stack expands to seal against casing with an inside diameter of 6.9 inches while holding a differential of 500 pounds per square inch and more.

Abstract: A device for sealing off an opening through the wall of a well tubular, which device comprises a tubular spacer having an outer diameter allowing the spacer to be arranged in the well tubular, a first seal collar assembly and a second seal collar assembly arranged opposite ends of the tubular spacer, each seal collar assembly comprising an activator ring and an annular seal collar, the activator rings being interconnected by a cylindrical system of shape memory alloy which system contracts when the temperature of the cylindrical system reaches the transition temperature of the shape memory alloy, and wherein each annular seal collar is arranged so as to be compressed against the inner surface of the well tubular upon contraction of the cylindrical system of shape memory alloy.

Abstract: A communication tool (100) for communicating hydraulic fluid through a tubing retrievable safety valve (50) is disclosed. The tool (100) has a first section (102) and a second section (132) that are initially coupled together. A set of axial locating keys (112) is operably attached to the first section (102) and is engagably positionable within a profile (62). A radial cutting device (148) is radially extendable through a window (152) of the second section (132). A circumferential locating key (140) is operably attached to the second section (132) and is engagably positionable within a pocket (66) of the safety valve (50) when the first and second sections (102, 132) are decoupled, thereby circumferentially aligning the radial cutting device (148) with the non annular hydraulic chamber (60).

Abstract: A particulate matter plug is placed along all or portions of a well to be permanently or temporarily abandoned, the plug being arranged to hinder/reduce fluid flow to surface. The plug consists of a mass of particulate matter composed of naturally occurring and/or synthetically produced granular matter, including gravel, sand, silt, clay and a mixture of these, and preferably of a poorly sorted mass of particulate matter. The granular particulate matter having average particle diameters included in the statistical range of variation of the mass is comprised of particles with an average particle diameter >1/256 millimeters, thus comprising approximately {fraction (2/3 )} of all particles in the mass.

Abstract: A hydraulically operated setting tool for use in setting a plug or other component in a wellbore, and which is responsive to a supply of input actuating pressure to actuate the tool. An elongate tool housing has an inlet to receive the supply of actuating pressure, and an actuator element is axially displaceable relative to housing and also engageable with the plug or other component to set and release the component with respect to the wellbore. A pressure multiplier arrangement includes a hydraulically operated low pressure and high volume output piston which performs initial loading of the tool, and a high pressure, low volume output piston which provides a multiplied hydraulic force applied to the actuator element to set the plug or other component in a required position in the wellbore.

Abstract: Disclosed is a method for coding video in which a predetermined algorithm is used to predict portions of the image based on information that will already be available to the decoder at the time of decoding the image. By using known corresponding algorithms in both coder and decoder, and only information that will be available to the decoder, the need to transmit detailed information regarding choices made in coding, e.g. motion vectors is avoided. However, a vector relationship can still be derived for use in the prediction. Prediction can be made based on an assumption that the content of the portion to be coded is similar to the content of an associated image portion, and by determining a vector relating the associated image portion to a reference image (both of which will be available to the decoder), the current image portion can be predicted from a further part of the reference image. The invention can be used in a form of modified pyramid coding.

Abstract: An improved downhole tool apparatus for limiting the extrusion of a packer element. The apparatus includes a packer mandrel having a packer element assembly disposed in a wellbore. Packer retaining shoes are disposed about the packer mandrel at the ends of the packer element assembly. The packer retaining shoes have an inner retainer and an outer retainer. The inner retainer has a plurality of segments having gaps therebetween that expand in width when the retaining shoe is moved from an initial position in which it is disposed about the packer mandrel to an expanded position wherein it engages the wellbore to limit the extrusion of the packer element assembly. The outer retainer is likewise made up of a plurality of segments having gaps therebetween that will expand. The inner retainer segments cover the gaps that exist between the outer retainer segments and the outer retainer segments cover the gaps that exist between the inner retainer segments so that extrusion is limited.

Abstract: A plug is provided for use in well plugging applications. In a described embodiment, the plug has a metal to metal seal on a hollow spherical structure. A change in contact pressure between the seal and a bore due to a change in differential pressure across the plug is regulated by changing characteristics of the plug structure.

Abstract: A composite bridge plug system for containing a well bore with reduced drill up time. The composite bridge plug system includes an elongate mandrel, a head member attached to a lower portion of the mandrel, an upper collar positioned about an upper portion of the mandrel, and a plurality of gripping members positioned about the mandrel. The gripping members are expandable outwardly when the mandrel is pulled upwardly with an engaging tube preventing the upward movement of the upper collar thereby compressing the gripping members. The upper portion of the mandrel includes a shear portion that is breakable by pulling upwardly upon the mandrel. An engaging portion surrounds the shear portion adjacent to the upper collar that is engageable with a lower slot within a head member of a higher bridge plug thereby preventing rotation of the higher bridge plug during drilling thereof.

Abstract: A communication tool (100) for communicating hydraulic fluid through a tubing retrievable safety valve (50) is disclosed. The tool (100) has a first section (102) and a second section (132) that are initially coupled together. A set of axial locating keys (112) is operably attached to the first section (102) and is engagably positionable within a profile (62). A radial cutting device (148) is radially extendable through a window (152) of the second section (132). A circumferential locating key (140) is operably attached to the second section (132) and is engagably positionable within a pocket (66) of the safety valve (50) when the first and second sections (102, 132) are decoupled, thereby circumferentially aligning the radial cutting device (148) with the non annular hydraulic chamber (60).

Abstract: A method of installing tubular conduits (e.g. casing, liners, sand screens) into a highly deviated borehole. A lower plug is attached at one end of a portion of a tubular conduit. This end is inserted into a borehole. After insertion of the length of conduit intended to be buoyancy-aided into the borehole, an inflatable plug insert is attached at the upper end. The inflatable plug has a built-in valve designed to enable fluid communication between the buoyancy-aided tubular section and the insertion string. A pump is attached to the built-in valve and the fluid within the section intended to be buoyancy-aided is removed, after which the built-in valve is closed. The buoyancy provided by the evacuated section enables insertion of the tubular conduit into boreholes greatly deviated from the vertical, reducing running drag and the risk of the tubular becoming differentially stuck.

Abstract: A method and apparatus for sealing well bores is disclosed. The apparatus comprises plates which initially have a width smaller than the diameter of the well bore to be sealed or plugged. The plates are fabricated from a mineral substance which has the property of swelling into an expanded state upon contact with and absorption of a liquid. The apparatus further comprises means for placing the plate within the well bore. Among the mineral substances which may be utilized for forming the plate are members of the group of clay minerals known as smectites, including sodium montmorillonite, calcium montmorillonite, sodium bentonite, and calcium bentonite. A method sealing a well bore with the apparatus is disclosed.

Abstract: A chemically inflated gas bag for mining is provided. This gas bag includes a modified PVA bag that contains sodium bicarbonate and an HDPE bag that contains acetic acid. The PVA bag and the HDPE bag are contained within a nylon/PE bag. Preferably, when the HDPE bag is broken, the flow of acetic acid onto the PVA bag is controlled by a second bag having small holes therein surrounding the HDPE bag, allowing the gas bag to be lowered into a borehole before it inflates. Another aspect of the present invention is a method of making this gas bag. This method includes pouring diluted acetic acid into an HDPE bag, putting sodium bicarbonate into a PVA bag, sealing these bags, and placing these bags within a nylon/PE bag. The gas bag is folded in such a manner as to easily inflate and completely seal the borehole.

Abstract: A well shut off device for completely sealing off a flowing well. The resilient center seal member is sandwiched between upper and lower face plates. A group of fastening members holds together the face plates and the central seal member for urging the central seal member into intimate sealing contact with the well casing of the well and with the couplings when the fastening members are tightened.

Abstract: A plug is provided for use in well plugging applications. In a described embodiment, the plug has a metal to metal seal on a hollow spherical structure. A change in contact pressure between the seal and a bore due to a change in differential pressure across the plug is regulated by changing characteristics of the plug structure.

Abstract: A bridge plug for use in a wellbore to isolate an upper portion of the wellbore from a lower portion. The bridge plug is run into the wellbore on wireline or run-in tubular and then set in the wellbore at a predetermined depth. In one aspect of the invention, the bridge plug includes a cylindrical body having a longitudinal bore therethrough which is sealed to the passage of fluid. A first and second lock ring assemblies are installed on the outer surface of the body and are designed to move in a single direction with respect to the body. A bidirectional slip member which provides resistance to axial forces in two directions and a sealing member is located on the exterior of the body. A sealing member is disposed between the first and second lock ring assemblies and is actuated by movement of the first ring towards the second ring.

Abstract: The present invention provides a downhole cementing apparatus run into a borehole on a tubular. The apparatus is constructed on the pipe in such a way that pressure surge during run-in is reduced by allowing fluid to enter the pipe and utilize the fluid pathway of the cement. In one aspect of the invention, an inner member is provided that filters fluid as it enters the fluid pathway. In another aspect of the invention, various methods are provided within the cementing apparatus to loosen and displace sediment in the borehole prior to cementing.

Abstract: A method of downhole fluid displacement and a plug utilized in the method according to which the plug is inserted in a pipe between two fluids for separating and displacing one of the fluids. The plug has a specific gravity of less than the fluid above it, so that, after the displacement operation, the plug floats to the top of the latter fluid for recovery.

Abstract: A plug is provided for use in conjunction with a subterranean well. In a described embodiment, a wellhead plug includes multiple outwardly extendable lugs for engagement with corresponding multiple oppositely facing shoulders formed internally on a bore extending in a wellhead. The lugs engage the shoulders to thereby resist pressure applied to the plug in the bore from above or below.

Abstract: A conventional thru tubing bridge plug is rendered in a more effective and useful downhole tool by incorporating a sensor module complete with preferably a plurality of downhole sensors to monitor downhole parameters such as but not limited to temperature and pressure both within the inflatable tool and in the annulus of the well created thereby.

Abstract: Sealing elements for well packers and bridgeplugs may be constructed with magnetorheological elastomers or foams disposed about electromagnet windings set in an internal mandrel. The elastomer or foam stiffness properties are formulated for a low setting force compliance in the absence of a magnetic field. After deployment, the tool winding is energized to engage the magnetic field and raise the stiffness properties of the elastomer or foam. When the magnetic field is activated, the packer or bridgeplug has greater structural resistance to unwanted pressure displacement. When the field is de-energized, the sealing element relaxes to permit resetting or removal.

Abstract: A communication tool (100) for communicating hydraulic fluid through a tubing retrievable safety valve (50) is disclosed. The tool (100) has a first section (102) and a second section (132) that are initially coupled together. A set of axial locating keys (112) is operably attached to the first section (102) and is engagably positionable within a profile (62). A radial cutting device (148) is radially extendable through a window (152) of the second section (132). A circumferential locating key (140) is operably attached to the second section (132) and is engagably positionable within a pocket (66) of the safety valve (50) when the first and second sections (102, 132) are decoupled, thereby circumferentially aligning the radial cutting device (148) with the non annular hydraulic chamber (60).

Abstract: Downhole wellbore tools are actuated by electrically controllable fluids energized by a magnetic field for example. When energized, the viscosity state of the fluid may be increased by a degree depending on the fluid formulation. Reduction of the controllable fluid viscosity by terminating a magnetic field acting upon the fluid may permit in situ wellbore pressure to displace a tool actuating piston. Displacement of the tool actuating piston is prevented by the controllable fluid in a viscous state. The viscous state of the fluid is energized by a magnetic field environment. When the field is de-energized, the controllable fluid viscosity quickly falls thereby permitting the fluid to flow through an open orifice into a low pressure receiving volume. In an alternative embodiment of the invention, an expandable volume fluid may be used against a slip actuating element in the same manner as a fluid pressure motor.

Abstract: A non-metallic element system is provided which can effectively seal or pack-off an annulus under elevated temperatures. The element system can also resist high differential pressures without sacrificing performance or suffering mechanical degradation, and is considerably faster to drill-up than a conventional element system. In one aspect, the composite material comprises an epoxy blend reinforced with glass fibers stacked layer upon layer at about 30 to about 70 degrees. A downhole tool, such as a bridge plug, frac-plug, or packer, is also provided. The tool comprises a first and second support ring having one or more tapered wedges, a first and second expansion ring, and a sealing member disposed between the expansion rings and the support rings.

Abstract: A plug for use in a borehole, the plug including a body member of a flexible material, the body member defining a floor portion, with a wall portion bounding and extending from the floor portion for engagement with an inner wall of the borehole for sealing the borehole. The invention also relates to a method of supporting materials in a borehole.

Abstract: The invention relates to a method for the formation of a plug (1) in a petroleum well (2) extending from the earth's surface or the sea floor to a petroleum reservoir, which well is lined with casing (3, 3′). At least one opening (4) is formed in the casing (3) at a distance from the earth's surface, and a liquid curable resin is provided in at least a portion of the opening (4) and an adjacent area of the well (2), whereby the resin after curing forms a plug (1) in the well. The invention also relates to a tool (9) for milling an opening (4) in a casing (3) of a petroleum well (2), and a plug (1) for plugging casing (3) of a petroleum well (2).

Abstract: A molten metal plug which expands upon solidification can be used to form a pressure resistant seal in a tubular such as is used in oil and gas exploration and production.

Abstract: Apparatus and associated methods are provided for remotely actuating a plug apparatus in a subterranean well. In a described embodiment, a plug apparatus has a plug member blocking fluid flow through one of two flow passages of the plug apparatus. A predetermined fluid pressure applied to one of the flow passages permits the plug member to be expended from the plug apparatus.

Abstract: A method and apparatus for use in a subterranean well is described. The apparatus typically includes a subterranean plug including a mandrel having an outer surface and a non-circular cross-section and a packing element arranged about the mandrel, the packing element having a non-cylindrical inner surface matching the mandrel outer surface such that concentric rotation between the mandrel and the packing element is precluded. The apparatus may include slips having cavities to facilitate quick drill-out of the plug.

Abstract: A bi-directional plug blocks the flow of fluid through a flow bore of a tubing string and can be opened by simple mechanical means requiring no external tools. A piston is slidably mounted in a piston housing and fixed in a first position with a plurality of shear screws. An atmospheric chamber formed within the piston housing creates a pressure differential causing the shear screws to fail when a certain pressure is applied to the surface area of the piston. When the shear screws break, the piston accelerates and strikes a scored, dome-shaped plug. The piston penetrates the plug, permanently pressing and housing pieces of the plug against the wall of a plug housing and opening the flow bore of the plug to fluid.

Abstract: Apparatus for use in operations performed in conjunction with a subterranean well is provided by the present invention. In one described embodiment, a plug apparatus includes a soluble polymer material, which is utilized in a plug member for blocking flow through a fluid passage. In another described embodiment, a soluble polymer material is utilized in a blocking member for blocking displacement of a displacement member of an apparatus.

Abstract: The invention comprises a tool for launching objects downhole, such as one or more plugs in a desired sequence. The movements leading to the release of the individual plugs are regulated by virtue of displacement of oil through at least one orifice. The wiper plugs are retained in the tool until such time as they are physically displaced beyond the lower end of the tool. The biased retainers holding the plugs within the tools are released upon a predetermined movement of the plugs beyond the lower end of the tool. If the retaining mechanism for the plug does not automatically release upon sufficient extension of the wiper plug from the tool, a pressure assist can be used to launch any given plug. The darts used to move an actuating piston to release the plugs are separated from the plugs and retained in the tool so that they do not need to be drilled out later.

Abstract: A cementing plug having a universal construction and improved wiping and extended wear characteristics. The cementing plug has a plug subassembly with a body member and an elastomeric jacket on the body member. The body member defines a central opening therethrough with a shoulder therein. To configure the plug as a bottom cementing plug, a shearable insert is positioned on the shoulder, and to configure the plug as a top cementing plug, a non-shearable insert is positioned on the shoulder. The shearable insert is one of a plurality of such inserts designed to shear at correspondingly different shear pressures. In a first embodiment, the shearable insert is a substantially flat disk having a uniform thickness, and in a second embodiment, the shearable insert has an outer ring portion and a relatively thin inner domed portion.

Abstract: The present invention provides a bridge plug for use in a well bore for engagement with the wall of a tubing extending down the bore. The bridge plug includes a sealing and an anchoring mechanism slidably disposed on a mandrel. The sealing mechanism includes sealing elements which are expandable radially outwardly to engage the tubing wall when the elements are compressed. The anchoring mechanism includes first and second sleeves axially movable relative to one another and having radially inwardly sloped first and second ramps respectively. The ramps define a recess therebetween and slips having complementary ramps are received into the recess. The first and second ramps cooperate to force the anchoring member radially outwardly into engagement with the tubing wall upon axial movement of said first ramp towards said second ramp. The plug also includes a ratchet for locking the sealing mechanism and the anchoring mechanism in engagement with the tubing wall.